The present invention relates to a sliding door actuating mechanism, and in particular to a control circuit for an actuating mechanism for sliding doors provided on the passenger side of conventional motor vehicles.
Certain panel-type trucks, which are generally referred to as vans, are equipped with a sliding door on the passenger side of the vehicle. Such a door is supported at three points, two support points having fixed arms which ride in tracks provided in the vehicle body. These tracks curve inwardly towards the front of the vehicle. The third support point involves a spring-loaded pivotally-mounted arm riding in a track on the vehicle body disposed on the exterior of the vehicle, either at the top or center of the vehicle side. When the door is being moved from its open to its closed position, the inwardly-curving tracks bring the front edge of the door into engagement with the vehicle body, and the pivotally-mounted arm allows the rear end of the door to be swung inwardly to latch the door in a position flush with the vehicle side. When the door is being opened, the rear edge of the door is moved outwardly while the front edge of the door is still engaged with the door frame in the vehicle body. Then, as the door is moved rearwardly, the door slides to the rear at an angle until the front edge of the door is disengaged from the door frame, and then becomes parallel to the side of the vehicle.
In such a door, it is necessary to apply a force to the rear edge of the door to urge it into engagement with the door frame, since seals around the edges of the door frame must be compressed to prevent entry of water and the like into the vehicle interior when the door is closed. To provide this force, the conventional latch mechanism includes a linkage so that motion of the door handle causes a hook-shaped pawl on the vehicle door to rotate and engage a striker pin on the door frame. Continued rotation of the pawl draws the rear edge of the door into engagement with the vehicle side. Alternatively, the necessary force for seal compression may be imparted to the door manually, by slamming the door.
It is desirable that such a sliding door be power-operated so that it can be opened and closed from a remote point, and without physical effort on the part of the operator. It is also desirable that such a door can be power-operated from the exterior of the vehicle to close it without the use of a key, without the possibility of damage to the control circuit or power operator if a closing control switch is maintained in operated condition by vandalism or the like. It should be noted that such doors, due to the door seals, may require considerable physical effort merely to bring the rear edge of the door into proximity with the door frame, so that rotation of the striker can pull the door to its closed position. A simple, inexpensive power-actuating mechanism for such a sliding door is desirable for use in vans used as taxis and shuttles between airport terminals and parking lots, particularly in inclement weather, and such an actuating mechanism is also desirable for use with vans used for recreational and other purposes. In particular, such an actuating mechanism is desirable in conjunction with modifications to a van to enable its use by a handicapped individual confined to a wheelchair.
Actuating mechanisms to operate a sliding door on a vehicle have been proposed. Typical of such mechanisms is U.S. Pat. No. 3,652,124, issued to Tronville, Mar. 28, 1972, disclosing an actuating mechanism for a sliding door on a small taxi. Tronville discloses a hand lever mounted adjacent to the driver's seat of the taxi, operating a plurality of flexible cables or rods, which in turn operate a mechanism for unlatching the door, and for pulling an edge of the door inwards for latching. Tronville also discloses the use of an electrical motor for moving the door between its opened and closed positions, either mounted in the vehicle body and operating a chain drive disposed on the exterior of the vehicle, or mounted in the vehicle door and provided with a pinion for engaging a rack mounted on the exterior of the vehicle.
Applicant's invention provides an actuating mechanism and a control circuit for the actuating mechanism that is simple and rugged in design, and is economical to manufacture, install, and maintain. Applicant's invention provides a sliding door actuator and control circuit which may be installed on a van at the time it is manufactured, or at any later time, without substantial modification of the conventional vehicle, and without disabling the existing manual operating mechanism, overcoming numerous deficiencies and complexities of known sliding door actuating mechanisms.